Control of trains



March 16 1926.

A. R. ANGUS CION'IROL OF TRAINS Filed Dec. 22, 1921 4 Sheets-Sheet 1 Mafch 16,1926. 1,576,805

A. R. ANGUS CONTROL OF TRAINS Filed Dec. 22 1921 4 Sheets-Sheet 2 March 16 1926.

1,576,805 A. R. ANGUS CONTROL OF TRAINS F iled Dec. 22, 1921 4 Sheets-Sheet 5 "Mamh16,1926. 1,576,805

A. R. ANGUS CONTROL OF TRAINS Filed Dec. 22, 1921 4 Sheets-Sheet 4 A He.

Patented Mar. 16, 1926.

ARTHURIREGINAIJD Aliens-:01"awns'rmmsmnm LONDON, ENGLAND.

CONTRQL' OFTRAINS.

Appl a i fi e i'Decemhen 22,13921. ise ffili'iNm? 5244228.

To alZwlwme't may con/00m:

Be .it vknown ,thatqI, ARTHUR REGINALD ANGUS, a subject of the i-King ';Qf'.;;G1e3/l3 Britain and Ireland, hand a mesident :of Westminster, in the 5 county :of ,iLonclen, England, ihavelinvented @oertaininew and useful Improvementstin tor Relating toithe Control" of v 'Irains, of which -the following is a specification.

fll'ii's invention,- Which :eonsistsof the in proveinents in itrainecontroll-in-gapparatus defined in the claims appended i-hereto is ill-ustratedeby the accompanyingi-achmvings, which represent diagrammatically examples 0t apparatus:accoiiclingythereto, Fig; 1 showing. anexample ofvtracknpparatus,; titain apparatusr suitable =fo1 use with-tithe apparatus gshownin, Eig.-,1, i-F-i-gu 3 itrainapparatus; for speed menthol,-iandmFig. ,4: track apparatus suitable formse in -;co-njunction 'Witl1,tl1e ,t-razin apparatus shownin Fig. 3.

v TheiapparatusshowninF his lie cenhfollingvthea passage of; trainsinhoth divestions walon g =,a single tiiaek between two plaoesuizand B. j lllzlettliilClQrlSillNl dGLhby in sulations into sections; andithea'ails 40f each side of the track are exeept-m'here separated by insulation, eonductively :connected "togethoi'. In: order that: for 11O 1f11'l21lz\VOl li'lng a ,tnainilocated ;;hetw,een insu'lationsj 118 and 6 near-A may -1',un: toniardsB; fl--S\Ylt- Ql1;lli11 A is-nioveid so that inter aliw-its-insulated Contact 3' efi eets contaetiwaithia contact hso that current passes qfI'O'Hlj jl- .sourceof, al ternatiup; current 1 by Y Wayoo'l tag-aw ire 2,; the contact 3 of: tlie-sW itclLia1u11 A, the: contact 4, wire 5,; to {the ;1-ai;-lsi ;7 elose tOslillQijlJlSlblk ti on 6, by -Way. ofgthe rails Zea wi'i'eil;l a contact 9, an insulated oontaetlO.ofitheswiteh arm A ,-;a wire 11,wt.W0':cntaCts 1112' and-13 (which are normally: iblldgfldqbyz (inconclustor 01" WllG'bUt ,;1na'y, he oonneeted together by, a. testing inst1n-1nent) awii1e: 1 l,;:the p121- lnal'y v Winding I 15 of, a qt ansfeniner gTT, 11 Wire 16, tothe rails 18;nearaninsulati n17, byuvay of theu'ails L8, a,\i i;1'e ;20, an'insulated ,contactQl of switch arm A,,,;;a Contact 22,-a \Vl16123, \theprimary *WljlldlllQjgQhwOfjiL trans-fennel- TT a: wilsey to;1the nails :26 near an insulation 19, lay-Way ofthe mile 26 a wire, 27, a :eontaet: =60; an? insulated contact 29,01 the switch; illllllh, a wirei-304 the primary Windingxilhoi ntvansferineri 21: "wire 82;;t0 :thei railsklil inearieanpinsulation 28, by, Way. ofa-thernai-ls 33-1t0:c=near;aminsw latione itheneeab-y wayqof a Wire Syihe priiinapyra nin ding1561M a. tnansi oriner; 'llT ilylle 3e5aatzeontactj 36,; an -i'nsulated icQ fifis' 37 0f th sw tc -man A, awWi-rerQ to nails 39 ..oppesiteutohinslll ,n 55,1-thenee iby -way oft the rails 39a to 1iea-r-uto flan insulatienAO thenceJoy"Wayzofi-awviiiejl;Ian-insulated, COD- tactAQ (of: the: sntehi arm. A eontacteifi, a--Wi33e Ad, and ta uine-gl5 back -to; the seurce 1. :If a eis in order the nelzgizationef th said c-t'nans femners .TT, KIT, gTaT?,,--; and TIT will ;cause ihy;,,i-nductien the; igespeetive; 11secondalry' windings 557, 58,159, and 58 z tmhe nergized ;.-n ac1n:,0 theseconcla yz circa 1 of these :transfenners may Joe ,pnovi'ded -.-vh eent-acts 'suoh as, the: contacts 12 ia nd, v13, 01 the; insertion; inarallel pf qtesti ng insgt1 umentsqeaoh iol which,v 'ifzgtheqtflaek be. unecoupied land.- iothermise 1 =;o1:el e1,-Will be leeted: by the stat e- ,0 f the insulation: deleting to vthe corresponding ;.primar y .go that wit may be ,dete 'rn inechWhethen e1- ;not ,QftOll lWd ative insulation ghas bngkeni p llow-n wholly 0;.- p artial -y. E The; division-0i the-trae be ween the iinsulations 6;;and ,55 jnto seotions -hy nleansvof the;i-nsulations.17, 1'9, and,;28 enables theaisfignalman :When= this part :of the ti ack; iswoecnpied :hy, a I, 'ailway wehiole, to detemiialie iby ,ehservingthe r:testing 1 inst en s:"he einbetere lnent enedw hepp mate ;l-ocatiQn -,Of -'-.the socoupying 53 9,11 e. lvihenallis in erdenand railW-ay vehioleis onany said: sectienigtested-zas above i1 licated then as thefifiiil: primary winding-56 (to ti er TT the wire 52, the contacts 801 and 802, the wire 805, the electromagnet 51, the Wire 50, the contacts 49 and 48 and the wires 47 and 45, but by suitably adjusting the relationship between the resistance 01 this path and that of the main return path through the rails 39 this current can be made of such a value that its efiect upon the energization of the electromagnet 51 is inappreciable. The energization of the electromagnet 51 causes its armature 46 to move so that it makes contact with a contact 181 and, inter alia, its insulated contact effects contact with a contact 76 and current passes from some suitable source of electricity 106 by way of a switch 109, a wire 77, the contact 76, the insulated contact 75 (of the armature 46), a wire 88, and awire 91, to the rails 39 (opposite the insulation 118), thence along the rails 39 to a point close to the insulation 40, thence by way of a wire 119, an insulated contact 120 (of the armature 46), a contact 121, a wire 122, and a wire 41, to the rails 39 (close to the insulation 40), thence along the rails 39 to a point opposite the insulation 28, and thence by way of a wire 108 back to the source 106. As in consequence of the energization of the electromagnet 51 the armature 46 makes contact with the contact 181, current flows through a circuit comprising the generator 1, the wire 2, the contact 3, a long contact with which the contact 3 is in contact, the armature 46, the contact 181, the wire 182, the electromagnet 51, the wire 50, the contact 49, the long contact 48, and the wires 47 and 45, so that it is possible by moving the switch arm further to the right, while maintaining contact between the contacts 3 and 4 and their corresponding long contacts to break the circuits of the primaries of the transformers TT, TT TT and TT, and at the same time to maintain the energization oi the electromagnet 51 ant thusthe circuit of the generator 106; the breakage of the circuits of the primaries of the transformers TT, TT, TT and TT interrupts the flow of testing current through the rails 7, 18, 26, 33, and 39. The current supplied to the train standing between the insulation 6 and 118 is adaptedto prevent the production of a warning or stopping operation thereon by apparatus adapted to produce such an operation in the absence of the flow therethrough of current suitable for restraining the production of such operation and thus permits the train to pass from A towards B up to the said insulation 28. One route for the transmission of current to the apparatus on the train isthus provided in the manner hereinbefore described that route being adapted for the supply of current from the generator 106 through the portion of the rails 39 located between points opposite to insulations 118 and 28. To enable the train to pass beyond the insulation 28 in the direction from A towards B, the railway track beyond the insulation 28 is provided with apparatus similar to that hereinbefore described. It the train should attempt topass beyond the insulation 28 when the road beyond this position is not made there will then be no electrical energy delivered to the rails beyond the insulation 28 (as by assumption this part of the track has not had a road made thereon) and so a warning or stopping operation will be produced on the train.

The movement of said armature 46 (when its electromagnet 51 is duly energized) closes, inter alia, part of the circuit relating to a source of electricity 107 through a simple switch 110 (whereby the circuit relating to said source 107 may be independently opened and closed), so that current flows from said source 107 by way of the switch 110, a wire 130, a contact 74, an insulated contact 73 (of the armature 46) and a wire 86 to the primary windings 93, 95, 96, and 99 of transformers TT, TT", TT", and TT respectively, thence by way of a wire 131 to an earth plate 132, thence by way of earth to an earth plate 112 and thence by way of a wire 111 back to the source 107 and thus the relative secondary windings 92, 94, 97 and 98 of said transformers TT*, TT TT, and TT respectively are energized and current flows as follows: (a) from the secondary winding 92 by way of a wire 133, to the rails 26 near the insulation 19, thence along the rails 26 to a point near the insulation 28, thence by way of a wire 90, a contact 700, aninsulated contact (of the armature 46) and a wire 89 back to the secondary wind ing 92: (b) from the secondary winding 94 by way of a wire 134 to the rails 18 near the insulation 17, thence along the rails 18 to a point near the insulation 19, and thence by way of a wire 101, a contact 82, an insulated contact 701 (of the armature 46) and a wire 100 back to the said second ary winding 94: (c) from the secondary winding 97 byway of a wire 135 to the rails 7 near the insulation 6, thence along the rails 7 to a point near the insulation 17, and thence by way of a wire 103, a contact 83 an insulated contact 702 (of the armature 46) and a wire 102, back to the secondary winding 97; and from the secondary winding 98 by way of a wire 137 to rails 138 near the insulation 118, thence along the rails 138 to a point near the insulation 6, and thence by way of a wire 139, a contact 140, an insulated contact 141 (of the armature 46), and a wire 142 back to the secondary winding 98. Thus when all is in order current for preventing the production on the train of a warning or stopping operation and so enabling the train to proceed on the down journeyi.-e., in the directionofrom A towards -Bmay be supplied to the rails on the side of the track oppositeto the railsto which current is supplied by thesource 106; in this way ansecondroute is'prov-ided for the transmission of current to the trainap mratus.

"Again in orderto supply current for enabling a train to proceed on thedown journey bymeans of a conductor 906 placed suitably adjacent to the-track rails a switch arm'143 istmoved and current passes from a suitable-source1d2-by Way of the switch arm 1e13, a'wire 104,;a contact 84:, an insulated contact (of the armature 46), anda-Wire 125 to the conductor 906, thence by'way ot' the wire 1 14:, to: the earth plate 132, thence by way of the earth to an earth plate 146, and thenceby way of a wire 114-? back \to the source 1432; in-this way third route is'provided for the transmission of current to thetrain apparatus. The restraining apparatus on thextrain has suitable receiving means, =as'induction coils,

suitably placed inn'elation to the rails of eachside of the traclcand to the conductor 900.

The operation of the switch arm A and, its connections for testing and making the roadin the direction :from -13 towards A are similar to thosejust describeditor testing and making-theroad inthe direction from A towards libnt the switch arm A islfor thatpurpose moved to, the left and the secondary 01% the transformer iTT (used for up journey testing) which corresponds in function to the transformer T T is adapted. to bel-connectedby means of conductors that do not include rails to an electromagnet 175 (used for the np journey) which corresponds in function tothe-electromagnet .5l.to which one pole of the secondary 433 of the-tran'stm-mer TT "is adapted to be connected by 'ay ofthe 'rails For the up journeyi.e.,tor the journey in the direction from 13 towards A -the train is supposedto be located between the insulations 28' and 55 and the testing is effected ot the track from the-insulation 28 to the insulation 118 and the train current is supplied from the insulation :55 to the insulation 6: forthe up road the generators 188,

900, and 901: correspond respectively to the generators 106,107, and 112 forthe down road,- anda conductor 902 extending along the track-close-to thesrailsof one side thereof corresponds to the conductor 906 for the down road.

,In the example shown in :Fig. 1, the sources of electricity'l, 106, 107, 1 1-2, 188,

900, and 901-aresources of alternating cur rent, the sources 106, 107,-and 1 12 being: adapted to supply alternating current of one frequency and the sources 188, 900, and 901 being adapted to supply alternating current of another frequency aitl'll the ap paratus'onr the trains being adapted to give clearance forthe two directions-;-of;travel only When 'receiving'current of the-one or the othenfrequency thatis ZLPPEGPl'lIlIGitO the direction of travel.

The. current used for track testing should be different, as in strength -or frequency, from current employed for giving clearance and should not he adapt-ed to produce clearance operations.

'In the example shown incl? 1 the in sulations 6, 7, 19,, and 28 are bridged-by conductors containing primary coils the-secondaries of which are in circuits each of which is adapted to operate an instrument adapted to indicate the'cond-ition of the -corresponding insulation Ol'ztllPlQSQHCQ ot-za trainion a corresponding portion of the track and the supply of clearance or may be controlled accocdingly. Inste therebeing primaries in the bridging ductors, those conductors may contain relays for the same purposes.

The presence of a vel-iicle on the portion or section ofthe track bet-ween the insulation 118 and 8 would normally asv hereiubcfore described,prevent :a train clearance current from being supplied to a locomotivesoas to enable it to approach the vehicle-on the up journey because the vehicle would shortcirouit' the primary. of the transformer. T1 or a corresponding; relay the energization of which is necessary for the energization of the electromagnet 1Z5 and-the consequent completiontol fL'Cll'Cll-lhriOl' supplying clearance current to the locomotive. To enable the locomotive, notwithstanding the presence of the 1 vehicle, to approach-the vehicle along that portion of. track, the-switch arm A is restored to its neutral position rand the switch arm 'ZlQismoved so that its insulated contact720comes into contact with a contact721-and its insulatedcontact172 i comes into contact with :a contact 725 and thus a circuit is completed allowing current to flow from an alternating-currentgenerator 114;,.by way of a wire 115,-and a wire 108, to the rails '39 wopposite the insu'lation 2-8, thence along the rails 39 to a point near the insulation 4.0, thence by way of a wire 720, the contac'ts'TfZ-t and 725,-andawire 727 tothe-rails 39 on the other side of the insulation 40, thence. along the rails 30- to a point opposite the insulation .118, thence by way of the wire 01, a---wire:117, id contact 728, aninsulated contact 729 on the switeharm A (only when theswitch. armrr is, as-shown, in

the neutral position), :a wire 723, the contacts T20 and 721, and a WireTQfZ back to the gen crater 11 1. The. alternating current thus supplied to the rails by the generator 114: differs from the alternating current or currents normally supplied for givingrthe locomotive clearance, and a clearance circuit on the locomotive will be closed partly owing to the abnormal position of a movable part of an instrument thereon that is adapted to be energized by the alternating current induced in the said instrument by the current in the rails and partly owing to the abnormal position of a special switch which must for this purpose be moved by the driver of the locomotive into the circuit-closing position. Similar means are provided, as shown, for enabling a locomotive to approach, on the down journey, a vehicle occupying the portion of track between the insuh'itions and 6.

In order that no train-clearance circuit may be made by the movement of the switch arm A from its neutral position except when the switch arm 719 is in its neutral position and that no trainclearance circuit can be made by the movement of the switch arm 719 except when the switch arm A is in its neutral position, the circuits of the electromagnets 175 and 51 are adapted, as'shown, to be closed by contacts carried by the switch arm 719 but to be so closed only when the arm 71.9 is in its neutral positioni. e., its neutral position in relation to the abnormalworking circuits that it is adapted in conjunction with the switch arm A to close for the purposes of this inventionand the abnormal circuits adapted to be closed by the switch arm 719 are adapted, as shown, to be so closed by contacts carried by the switch arm A but to be closed only when the arm A is in its neutral positioni. e., its natural position in relation to the normal-working circuits that it is adapted to close.

The alternating train-clearance current caused by the generator 114: or the generator 113, according to the position of the switch arm 719 and to the direction in which it is desired that the locomotive shall travel, to flow through the rails 39 as hereinbefore described, induces in an induction device 360 (which is shown diagrammatically in Fig. 2 as a single coil although it may, of course, comprise more than one coil) of the train a corresponding alternating current which, by means of wires 361 and 377, flows to and from an instrument 382 having a movable part adapted, if the instrument be energized by currents of the different frequencies to be employed, to occupy diiferent positions respectively. \Vhen the instrument is energized by current of the frequency to permit the train to travel in the down direction its movable part moves an arm 300 into a position in which its insulated contact plate 302 makes contact with a contact 801. A switch arm 803 is adapted to occupy a normal-working position as shown in full lines in which it makes contact with a contact 909 and an abnormal-working position shown in dotted lines in which it makes contact with a contact 807 and into which it is moved by the driver of the locomotive when it is desired that the locomotiveshould appr ach a vehicle occupying a portion of track that the locomotive would normally be prevented from entering by its occupancy. When the switch arm 803 is in the abnormal-working position and the instrument 382 is energized as aforesaid, the production of a stopping operation is prevented if the speed of the locomotive does not exceed a certain low speed corresponding to a contact plate 333, whilst it that speed is exceeded the production of a stopping operation is no longer restrained and the locomotive is prevented from proceeding: if the speed of the locomotive does not exceed the aforesaid low speed, current flows from a generator 305 on the locomotive by way of a wire 306, an electromagnet 324: (which, when energized, is adapted to restrain by means of its armature 313 the production of a stopping oper- .tion), a wire 325, the switch arm 303, the

contact 807, a wire 320, an insulated contact 319 on an arm 318 the position of which depends on the speed of the locomotive, the contact plate 333 (in contact with the insulated contact 319 only when the speed of the locomotive does not exceed the low speed to which the contact plate 33 corresponds), a wire 339, a contact 700 carried by but insulated from a switch arm 400 adapted to be in one or the other of two different positions in accordance with the direction of running of the train (as by being connected with the reversing gear of the locomotive), a contact 379 with which the contact 700 is in contact when the reversing gear of the locomotive is set for the train to run in the down direction, a wire 802, the contact 801, and back to the generator 305 by way of the insulated contact plate 302, and a wire 30%: if the speed of the locomotive exceeds the aforesaid low speed the arm 318 moves its insulated contact plate 319 out of contact with the contact plate 333 and thus breaks the, circuit of the electromagnet 324 and a stopping operation is consequently produced on the locomotive. If the rails 39 are not supplied with current for the abnormal working, the arm 300 (which when the instrument 382 is not energized is held by gravity against a stop) is not moved so as to bring its contact plate into contact with the contact 801, and, as, consequently, the electromagnet 32a is not energized, a stopping operation is produced on the locomotive.

During the normal-working for travel in the down direction the inducing current is of such a frequency as to cause the arm 300 to occupy a position in which its insulated contact plate 302 makes contact with a contact T-lS andthe switch arm 803 is in the positionindicated by full lines in Fig. 2.; current consequently flows from the gener= ator 305, by Way otthe' Wire 5306, the electro- H. 7.1, J x i magnet 324-, the mieln w, tne switch arm and backto the generator 305 by way of the wire the production o1. a stepping operation thus being restrained.

(to operation ot t he" apparatus Wnen the train-is running in the up direction is similar to that-describedwith reference to the down direction, the switch arm 400 being; inthe position in which its contactsZOO and k make contact with contacts 375 and 36 respectivelywhen the Reversing gear is set tor-the train to run in the up directioi'i, and when the instrument is encr iaed by currents ot'frequencie's to permit the train. to travel'in the up direction the arm 2300 is moved. so that its insulated contact plate 302 makes contact- With a cont-act 805 for current oi the frequency for abnormal working, and'with' acontact 74?? for current ol the frequency for normal Working.

If itis not desired to limit-the speed lier the abnormalWorking; the Wire 2320 should be connected with the xvii-e333) directly and not, as shown, through the contact plates 319 and 333.

From the foregoing description 01 Figs. 1 and 2 it Will be seen thatthe train apparatus includ-esdan-ger indicating means (a Warning device a-nd/ or a stopping device adapted to comeinto operation unless electrically re-' strained, and the apparatus on. the track, whereby a Signalman/is enabled to control the passage oi the said train along a portion oftrack (e. g1, the road extending between insulations-G and28-shownin Fig. l), includes trafiic-controlling electro-responsivemeans (for example, 'lT of 1) adapted to be energized and de-energized by th movement of switching means by the signaln'ian butto lie-prevented frem being energizedflvhen eitherthe said'portion of track or the portion next inadvance the-roof thesection between insulations 28 and shown in Fig. l) is notdn order, as byheino; occupied by a railway VGl'llClG, and oiny Whenenergized to cause the completion of a circuit for res straining the operation oi the danger indi-catingdevice on the said train; and that for the purpose oi incrcau eon-trol'ot the running ol trains aloi'ig the said portion of track Iprovide, on the tracer, apparatus to enable the signahnan to cause currents differing (as of frequency) for the tvo directions of travel of rains to passto the train apparatus, and, on the train, apparatusaoaptcd to enable the elec trica l restraint oi the operation ot the Warning vand/or the stopping device to be effected'only' When'the current thus caused to pass is appropriate to the direction ot travel for which thetrain' is set; it 'W'l'll' furtherhe seen that, although the occupancyof the said portion of'track causes the deenergization of the traiiiocontrolling-electro-responsive means, the said trainitself is alt-loved to proceed alonggthe-saidy portion of track owing to the fact that I provide-,as hereinbei'ore described, means (81; 122505 Fig". 1) for enabling the restraining circuitafter being made by the traffic-controlling electro-responsivemeans' to be maintained by the signalman.

It will also be seen that-'t-hetrain-control ling apparatusis adapted to enable'a sigi nalman and a locomotivedriver toad-just the track and'locomot-iveportions thereof (719 of Fig.1 and 803 ot Fig. 2) respec tively to (Jo-operative abnormal positions and thus to cause a portion (324' ofFig: of the apparatus located-on tlielocomoti've to be energized by electricity andtherehy' to enable the locomotiveto"approach a vehicle occupying a portion of track, and that in order to impose suitably low speed limit on thelocomotivein'this case, Iprovide meansfor.causing a-stoppi-ng op eration to be performedon the "locomotive if the locomotive travel at a speed I that is greater than-apredetermined low speed, notwithstanding the adjustment 01 the track and'locomotive portionsot tlre traincontrolling apparatus to the co-op erative -ab-- normal-positions.- f

It Willfurther. be seen that, .in-thecase of train-controlling apparatus comprising a train-carried device (313 of'Fig; theproduction by which of a dangerindication dependentupon the conditionas to elec triii'cation Of apparatus (82 lo'f l i 2) i on the train, theretare provided means-adapted to furnish alternative independent track routes any one o-f'vvhich may atwi be used for transmitting current to att'ect-theco-ir: diti on as to eleetrification=oi the aforesaid apparatuson the'train as required in re spect of the production of the dangerindication so that the control ofthe train bythe aforesaid train-carried device in the normaliminnei can be produced from the track so long as any one-offthe said -routes remain intact.

Fig. 3-shows train apparatus suitable for: use on a track coniprisin *-a-porti'on"along which it is iHtQDC edto limittlre speedotatrain running thereover andwh ich is di' vided by insulation into anWarningsectionand a stop section, the'Warningsection -be-' ing one in which it is intended that atrain travelling a speed exceeding the pert-inent'speed limit should automatically have section being one in which it'is intended that such a train should automatically be stopped or have an emergency application of the brakes produced thereon. The rails of the warning section being energized by alternating current of a frequency corresponding to the speed limit in question, as will hereinafter be described with reference to Fig. 4, this current induces in an induction device 360 (Fig. 3) (Which is shown diagrammatically in the drawing as a single coil although it may, of course, comprise more than one coil) an alternating current of the same frequency, which, by means of wires 361 and 377, flows to and from an instrument 382 having a movable part adapted to occupy certain definite and dilferent positions if the instrument be energized by currents of the several frequen cies to be employed respectively. The movable part of the instrument 382 has connected with it an arm 300 which consequently always occupies a position corresponding to the frequency of any current for the time being energizing the instrument 382 and therefore corresponding also to the speed limit to which the frequency in question has been assigned. Thus when the instrument is energized by currents of frequencies corresponding, for the restraint of a warning operation in the case of one direction of travel (hereinafter referred to as the down direction), to speed limits, of, for example, 15 miles an hour, 30 miles an hour, and 45 miles anhour respectively, the arm 300 (which when the instrument 382 is not energized is held by gravity against a stop) occupies positions in which its insulated contact plate 301 makes contact with contacts 346 and 347, contacts 343 and 344, and contacts 340 and 341 respectively. Corresponding respectively to the various speed limits there are provided a pair of concentric contact plates 332 and 333 of equal angular extent, a pair of concentric contact plates 330 and 331 of equal angular extent, and a pair of concentric contact plates 328 and 329 of equal angular extent. All the concentric contact plates are insulated from one another and the angular extents of the several pairs are limited to corre spond to the respective speed limits. A speed-indicating part 318 the position of which depends on the speed of the train carries insulated contact plates 314, 315, and 316 adapted to make contact with the contact plates 328, 330, and 332 respectively,

and contact plates 322, 321, and 319 adapted to make contact with the contact plates 329, 331, and 333 respectively. An electro-magnet 310 is adapted when energized to prevent its armature 312 (which constantly tends to cause the production of a warning operation or a service application of the brakes) from causing the production of a warning operation or a. service application of the brakes; and an electromagnet 324 is adapted when energized to prevent its armature 313 (which constantly tends to cause the production of a stopping operation or an emergency application of the brakes) from causing the production of a stopping operation or an emergency application of the brakes. When the train is on a warning section along which it is desired to limit its speed when running in the down direction to thirty miles an hour, the frequency of the current supplied to the track rails, by means hereinafter described with reference to Fig. 4, is such as to cause the arm 300 to occupy a position in which its insulated contact plate 301. makes contact with the contacts 343 and 344 which correspond to a speed limit of thirty miles an hour. If now the train is travelling'at a speed not exceeding thirty miles an hour the'speed-indicating part 318 occupies such a position that its insulated contact plate 315 makes contact with the contact plate 330 and, if a switch arm 400, adapted to be in one or the other of two different positions in accordance with the direction of running of the train (as by being connected with the reversing gear of the locomotive), is in the position corre sponding to the down direction of running of the train which is that for which its contacts 700, 701, 702, 703, 704, 705, 706, and 707 are in contact with contacts 375), 378, 376, 375, 374, 373, 601, and 602 respectivel current flows from a generator 305 on tie train along a wire 306 and thence (a) by way of a wire 309, the electromagnet 310, a wire 311, the contact plates and 330, a wire 336, the contact 702 of the switch arm 400, the'contact 376, a wire 326, the contact 343, the insulated contact plate 301, and wires 303 and 307 back to the generator 305, and (b) by way of a wire 308, the electromagnet 324, a wire 323, a wire 760, the contact 706 of the switch arm 400, the contact 601, the wires 503, 504, and 505, the contact 344, the insulated contact plate 301, and the wires 303 and 307 back to the generator 305. In this way a warning opera tion or a service application of the brakes is restrained by virtue of the travel of the train in-the down direction at a speed that is not greater than the speed limit, for a train running in the down direction over that portion of the track, namely thirty miles an hour, whilst a stopping operation or an emergency application of the brakes is restrained independently ofthe speed of the train. If the speed of the train exceeds thirty miles an hour the speed-indicating part 318 occupies such a position that its contact plate 315 does not make contact with the contact plate 330 and consequently the described path through the electromag ence toFig: at) are provided for supplying the rails'thereo-f with alternating currents of frequenc1es,= for 'the down direction of travel of th'e'train', such asto causethe arm 300 to occupy positions in wl'ii ch its insulated'contact SOQ make's contact with contacts 730 and 3-:l8only for a speed limit oi iifteeir miles an'hour, with: contacts 731- an'd345 1 only for a' speed limit of thirty miles an hour, and witlrcontacts'732Iand 8 i2 'only" for a speed limitoi iorty five mil'es anhour, the contact 301:n'ot bein'giin' contact with any contact in anyof thesecas'es, Itthe speed limit 1 for the pfo-rtionof track is thirty miles an hour the ar-mi 300 isxin such'a position that its insulated contact plate 802 makes contact with the contacts 781 and 84st).- It'now' the train' is travelingcat as speed not exceeding thirty' miles hour, the speed indicating part 318 occupies such a position tliatitsinsulated contact plate 321 makes contact with'the"contact=plate and our rent fro1n' tl1e generator 305 'flows' by way oi the wire'306, the 'wire 308; the electro magnet 324-, the wires 323 and 502, the insulated contact pilate 32l,the contact late 331, a wire 33?, theicont-act'703-ot the switcharm 400, the conta'ct 375, 2r wi're"'736, the contact731, the insulated'contact 302, and

the 'Wll'GS 304 and 307 ba'ck to the: enerator 305. A: stopping :operation oran emergencyapplication' of the brakesis thus restrained by virtue of the I travel. of: the train in :the down directionat avspeed that is not-greater than the speed limit lor atrain'runniingiin the down directionover that portion of track, namely thirty males an hour. @urrcnt from the generator 305 at the san'1etime passes byway of the wires 300 and 309, the

electromagnet 310, the wi.re '733-, the contact 707 of the sw1tcl1 ar1n i00, the'contact 609/, and'the wires 500, 507 and 508 tothe:

contact 345 and thence by way 'o'fithe con tact 302'and tlre'wires2305Vand 30"? b'acleio' the generator 305 so that the'electrom-agnet 310 is energized and the warning. operation. is consequently restrained;'the Warning: operation is similarly restrained when the contact 302 is'in contact with any of the-other pairs of contacts to wli icl1:itre'- lates. It the speed of the train exceeds thirty miles an hour the speed-indicating part 318 occnpies'such a position that its contactp=late321 does'n'ot make contaetavith the contact plate 831 and consequently the=de scribed patlrthrough the electromagnet 324 is broken and a stopping operation or an emergency application o-i'the brakes is con sequently' produced on the train.

The track rails ofa'portion of traclcin which it is notdesired to limit the speed ofa train running in the down direction for example, thatportion ofthe track over whioh'the train runs on leaving a curveare energized by alternating current of a frequency such as to cause the arm 300 (Fig; 3)'to be moved into the position-in which its insulated contact plate 302' makes contact with contacts 900 and 901; in this case current flows from the generator 305 through a wire 806 thence (L) by way of the wire 309, the electromagnet 310, the wire 733, the contacts 707 and 602, the wires 506 and 507,11 wire 905, the contact 90L the contact plate 302, and the wires i: and 307 back to the generator 305 and (b by way of the wire 308, the electromagnet 324-, the wires 3-28 and 760, the contacts'700 and601, the wires 503 and' i, a'wire 904:, the contact 900, the contact'pl'ate 802, and

the wires 30i'and 307 back to the generator 305. Thus the energization of the electromagnets 310 and 324;, and consequently the restraint of both a warning. operation and a stopping operation, is eftected on'the train by' circuits which do not include any of the concentric co'ntactplates 328 to 333 inclusive so thatthe-restraint of b oth warning and stopping -operations is this case independen't'ofthe speed'of'the'train'.

In orderto enable the magnets 310 and 32 t to exercise their restraint while the arm 300 is moving from one speed-limiting position to -another they may be rendered slow-actingas by'providing them with shunts 709 and 710 respectively containing suitable llOlT-lllCiElGtlVG resistances.

For controlling: the running of a train in the up directionalternating currents at (t-different set of frequencies supplied to re track-rails, and't-he alternati' genrren'ts' consequently induced in the deviee 300 (Fig. correspoiiding"to speed lifniits o't fifteen miles an hour, thirty miles anhour,

gear of the train-is set'i'or the train to run in the up direction, and the contacts 351,

and 359 being connected with the contact 605, and the contacts 353, 357, and 366 being connected with the contact 604, and the contacts 706 and 707 of the switch arm 400 being adapted to be in contact with the contacts 604 and 605 respectively when the reversing gear of the train is set for running in the last mentioned direction.

The alternating current supplied to the track rails to enable a train to travel at an unlimited speed in the up direction differs from that supplied for enabling a train to travel at an unlimited speed in the down direction and is of such a frequency as to cause the arm 300 3) to be moved so that its contact plate 302 makes contact with contacts 902 and 903 which are connected by wires 906 and 907 with the contacts 605 and 604 respectively, and the restraint of both a warning operation and a stepping operation is effected on the train, it the switch 400 is in'the position corresponding to the up direction of running, in a manner similar to that described with reference to the down direction of running.

It will be seen that it the switch arm 400 (Fig. 3) is in a position that is not in agreement with the direction in which it intended that trains should run along the track no circuit is completed through either of the restraining magnets 310 and 324 because the contacts with which the insulated plates 301 and 302 of the arm 300 are in contact are not, owing to the position of the switch arm 400, electrically connected to the contacts of the switch arm and consequently neither a waring nor a stopping operation is restrained on the train,

Fig. 4 shows a part of a track including a curve equipped with apparatus adapted to control the speed and direction of running of a train provided with the apparatus such as that shown in Fig. 3 when passing over the curve in either direction he apparatus is adapted to impose a certain speed limit upon a train running along the portion of track between an insulation 54 and an insulation 58 in the down direction (from the insulation 54 towards the insulation 58), this portion being for that purpose divided by an insulation 56 into a warning section and a stop section (namely, the section I between the insulatious 54 and 56 and the section II between the insulations 56 and (b) to allow that train to travel at an unlimited. speed between the insulations 58 and 62, (c) to impose a certain speed limit upon a train running in the up direction along the por tion of track between the insulations 62 and 58, that portion being similarly divided into a warning section (section III) and a stop section (section IV) by the insulation 60, and (d) to allow the last mentioned train to travel at an unlimited speed between the insulations 58 and 54. The track rails are adapted to be energized by alternating currents of the several different frequencies necessary to effect this control from the sources of alternating current 1, 2. 3, 4, 5, and 6 as will now be described.

To set the track apparatus to control the running oi a train in the down direction a switch arm A (Fig. 4) is moved to the left so that contacts 31 and 39, 43 and 51, 19 and 27, and 8 and 16 carried by but insulated from the arm A ettect contact with contacts 32 and 38, 44 and 50, 20 and 26, and 9 and 15 respectively,and current flows, inter alia, from the source 3 by way of a wire 7, the contacts 8 and 9, and wires 10 and 11 to rails 12 of section I at a point near the in sulation 56, thence along the nails 12 to a point near the insulation 54, thence by way of wires 13 and 14, the contacts 15 and 16 and a wire 17 back to the generator 3; current at the same time passes from the source 2 by way of a wire 18, the contacts 19 and 20, and wires 21 and 22 to the rails 23 of section II at point near the insulation 58, thence along the rails 23 to a point near the insulation 56, and thence by way of wires 24 and 25, the contacts 26 and 27 and a wire 28 back to the source 2. The sources 3 and 2 are adapted to supply alternating currents of frequencies corresponding to the speed limit assigned to sections I and II and also to the down direction of running of a train, and such as to cause sections I and II to act as warning and stop sections respectively; if the limit of speed is 30 miles an hour, as in the ease of the example described with reterence to Fig. 3, the frequency of the current supplied from the source 3 4) to the rails 12 of section I is such as so to energize the instrument 382 (Fig. 3) of a train-running thereover that its arm 300 moves into the position in which its contact plate 301 makes contact with the contacts 343 and 344, and the frequency of the current supplied from the source 2 (Fig. 4) to the rails 23 of section II is such as to cause the arm 300 (Fig. 3) to be moved into the position in which its contact plate 302 makes contact with the contacts 731 and 345. Current also passes from the source 1 (Fig. 4) along a wire 29, thence (a) by way of a wire 30, the contacts 31 and 32, and wires 33 and to l'ltlllS 35 of section IV at a point near the insulation 60, thence along the rails 35 to a point near the insulation 58, and thence by way of wires 36 and 37, the contacts 38 and 39, and wires 40 and 41 back to the source 1, and (Z2) by way of a wire 42, the contacts 43 and 44 and wires 45 and 46 to rails 47 of section III at a point near the insulation 62, thence :along the rails 47 to a point near the insulation 60, and thence by Way of Wires 48 and 49,

the contacts and al, a wire 52, and the wire 4i back to source 1. The, rails and 47 of sections. 1V and HI arelthustraversed by alternating current from the source 1, which supplies current of" si ich. a frequency as to enable a train running in the down direction to travel at an unlimited speed, i. e, of such a 't'requency as to c ause the instrument 382 (Fig. on the train to be so energized as to move its arm 300 so that its contact plate makes contact with the contacts 900 and 901. 'lhus the apparatus on the. track (Fig. 4.) is adapted to control the passage of a train approach ing the curve in the down direction from the insulation 54- to the insulation 62 so that ii the train exceeds the speed limit assigned to sections I and ll on section I a warning operation is effected thereon, if it exceeds that speed limit on section ll :1 stopping operation is effected thereon, and so that the tuain may run at an unlimited speed away from the curve over sections IV and Ill.

To control the passage of a. train when rrmning in the up direction the switch arm A (Fig. l) is moved to the right so that other cont-acts carried thereon but insulated there "from make contact with another set of contacts and thus cause the completion of circuits which are similar to those described with reference to the control of a train running in the down direction, and which enable the sources (3 and 5 to supply currents oi frequencies, corresponding to the speed limit assigned to the sections IV and III" for the up direction of running, to, the rails of the last mentioned sectionsQthe frequencies being such as to make the sections a warning section and a stop section respectively, and the source 4 to supply current to the rails of sections II and I of a frequency to permit atrain to travel at an unlimited speec when running over the last mentioned sections in the up direction It is obvious that the parts of the track beyond the insulations 54L and 62 l) n' ay be adapted so that a train may travel thcreover at an unlimited speed, the rails thereof being energized for that purpose with alternating currents of the correspond ing frequencies either from the sources -l and 1 respectively or from similar sources located elsewhere, and that apparatus for, controlling the speed ot a "train at anyother parts of the track where maybe desired may be provided at those parts and the sources corresponding to the sources 2, 3, 5, and (3 adaptedto supply alternating currents of the frequencies corresponding, for the two directions of travel of a train, to the speed limits that it is desired to impose upon ea. train when running; over those parts.

Instead of employing alternating cur 'ents of dili'ering sets of frequencies for the opposite directions of-travel, alternating currents 'o'l one set of strengths may be employed for permitting and controlling the running of trains in the down direction and alternating currents of another set of 'tliseinployed for permitting and conthe rui' ning of trains in the up dithe instrument 382 (Figs. 2 and 3) being then adapted, when energized by currents o'f various st'rengths induced by the track currents oi the several strengths einployed respectively, to cause its arm 300 to make contact with its several contacts respectively as hereinbefore cescribed with reference to currents of the several frequencies mentioned.

in Figs. 2 and 3 the induction device 360 is (liagrammatically represented as a single coil only but in order to obtain the best results there should be placed on the locomotive and also it required on a. vehicle or vehicles attached'thereto a number of coils which may extend an along the locomotive and should be placed as close as practicable to the track rails and/or the conductor arranged close thereto and of course on both sides of the locomotive it the rails on both sides of the track are to be employed.

the case of the apparatus described with reference to 3 it will be seen that when current commences to flow through the electromagnetillO and thus to cause its cnergization current also flows from the wire 309 by way of a path the completion of which was caused by the last previous dcenergization of the electroinagnet 3'10 and which comprises a wire 390, a contact 391, a resilient contact a wire 394, a lineclear hell or huzzer "7112, and a wire 395 to the wire 738, and a line-clear indication is thus given which caused to cease "by the interruption of this path w ien the arl'nature 3 12 moves in consequence ofthe energiza tion of the electromagnet 310 and removes the resilient contact 392 from thecontact by moving the arm 393; alternatively the circuit of the line-clear hell or buzzer can be inroken after the completion of the circuit of the battle at o by other means as by pressure of a. puh button by the driver.

l'henthe invention used. in ccamection with electric trains the current supplied to the track rails for the purposes of this iuvention should, of course, so diifcr from the propulsion current as not to be interfered with thereby as "far as the operations hereinbefore described are concerned for example, if alternating or pulsating unidirectional current at one frequency is used for the propulsion,alternating or unidirectional pulsatin'g current at frequencies different from that used for propulsion should be used for the train-controlling currents and, except inthe case of the conductor parallel to the track, train-controlling currents are .lOO

lib;

preferably supplied by means of transformers or induction coils at a higher voltage or voltages than the propulsion current.

I claim 1. Electrical train-controlling apparatus comprising on a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained and on the track apparatus for enabling a signalman to control the passage of said train along a portion of track including switching means and traiiic-controiling clcctro-responsi ve means adapted to be included in circuit and excluded from circuit by said switching means, to be energized when so included in circuit and both said portion of track and the portion next in advance are unoccupied by a railway vehicle and then to cause the completion of a circuit for restraining the operation of said dangerindicating device on said train, and to be tie-energized both when excluded from circuit and when either of said portions of track is occupied by a railway vehicle, substantially as described.

2. ilLPpflltL tllS according to claim 1 comprising means adapted to enable said rcstraining circuit after being made as aforesaid to be maintained by the signalman so that the restraint of the operation of said danger-indicating device can be maintained during the passage of said train along said portion of track notwithstanding the deenergization of said traiiiccontrolling electro-responsive means, substantially as de scribed.

Electrical train-controlling apparatus comprising on. a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained from the track and on the track apparatus for enabling a signalman to control the passage of said train along a port-ion of track including switching means, traflic' controlling electroresponsive means adapted to be included in circuit and excluded from circuit by said switching means, to be energized when so included in circuit and said portion of track is unoccupied by a railway vehicle and then to cause the completion of a circuit for restraining the operation of said danger-indicating device on said train, and to be Clo-energized both when excluded from circuit and when said portion of track is occupied by arailway vehicle, and means adapted to enable said restraining circuit after being made as aforesaid to be maintained by the Signalman so that the restraint of the operation of said danger-indicating device can be maintained during the passage of said train along said portion of track notwithstanding the de-energization of said tratlic-controlling electro-responsive means, substantially as described.

4:. Electrical train-controlling apparatus comprising on a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained and on the track apparatus for enabling a Signalman to control the passage of said train along a portion of track including switching means, traiiic-controlling electroresponsive means adapted to be included in circuit and excluded from circuit by said switching means to be energized when so included in circuit and both said portions of track and the port-ion next in advance are unoccupied by a railway vehicle and then to cause the completion of a circuit for restraining the operation of said danger-indicating device on said train, and to be decnergized both when excluded from circuit and when either of said portions of track is occupied by a railway vehicle, and means adapted to enable the Signalman, by moving said switching means after the completion of said restraining circuit, to exclude said traffic-controlling electro-responsive means from circuit and at the same time to maintain said restraining circuit, substantially as described.

5. Electrical train-controlling apparatus comprising on a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained from the track and on the track apparatus for enabling a signalman to control the passage of said train along a portion of track including switching means, trailic-controlling electro-responsive means adapted to be included in circuit and excluded from circuit by said switching means, to be encrgized when so included in circuit and said portion of track is unoccupied by a railway vehicle and then to cause the completion of a circuit for restraining the operation of said danger-indicating device on said train, and to be de-energized both when excluded from circuit and when said portion of track is occupied by a railway vehicle, and meansadapted to enable the Signalman, by moving said switching means after the completion of said restraining circuit, to exclude said tratlic-controlling electro-responsive means from circuit and at the same time to maintain said restraining circuit, substantialh as described.

6. Electrical train-controlling apparatus comprising on a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained and on the track apparatus for enabling a Signalman to control the passage of said train along a portion of track including switching means, traflic-controlling electroresponsive means adapted to be included in circuit and excluded from circuit by said switching means, to be energized when so included in circuit and both said portion of track and the portion next in advance are nneccu iied by a railway vehicle and then to cause the completion of a circuit for restraining the operation of said danger indicating device on said train, and to be deenergized both when excluded from circuit and when either of said portions of track is occupied by a railway vehicle, and means adapted to enable the signalman to cause currents differing (as in frequency) for the two directions of travel of trains to pass to said apparatus on said train, said apparatus on said train being adapted to enable the electrical restraint of the operation of said danger-indicating means to be efiected only when the current thus caused to pass is appropriate (as in frequency) to the direction of travel for which said train is set, substantially as described.

7. Electrical tlzll1lCO11t'l0lling apparatus comprising on a train apparatus including a danger-indicating device adapted to come into operation unless electrically restrained from the track and on the track apparatus for enabling a Signalman to control the passage of said train along a portion of track including switching means, traffic-controlling electr-o-responsive means adapted to be included in circuit and excluded from circuit by said switching means, to be energized whenso included in circuit and said portion of track is unoccupied by a railway vehicle and then to cause the completion of a circuit for restraining the-operation of said dangerindicating device on said train, and to be deenergized both when excluded from circuit and when said portion of track is occupied by a railway vehicle, means adapted to enable said restraining circuit after being made as aforesaid to be maintained by the signalman so that the restraint of the operation of said danger-indicating device can be maintained during the passage of said train along said portion of track notwithstanding the de-energization of said trafiic-controlling electro-responsive means, and means adapted to enable the signahnan to cause currents differing (as in frequency) for the two directions. of travel of trains to pass to said apparatus on said train, said apparatus on said train being adapted to enable the electrical restraint of the operation of said danger-indicating means to be effected only when the current thus caused to pass is appropriate (as in frequency) to the direc tion of travel for which said train is set, sul'istantially as described.

8. Electrical train-controlling apparatus comprising a warning device and a stopping device each adapted to come into operation when not under electrical restraint, a speedresponsive part adapted to change its position in accordance with the speed of the train, and a speed-limiting electromagnetic device adapted in accordance with its energization by specific different currents corrents for a specific speed limit and cor respondingly two different speed-limiting positions of the said movable part in the first of which it is adapted by itself to cause the electrical-restraint of the operation of said stop-ping device but to co-operate with said speed-responsive part in causing the electrical restraintof the operation of said warning device only when said specd responsive part is occupying a position that corresponds to a speed not greater than the speed limit represented by the position for the time being of said movable part and in the second of which it is adapted to co-operate with said speed-responsive part in causing the electrical restraint of the operation cit said stopping device only when said speed-responsive part is occupying a position that corresponds to a speed not greater than the speed limit represented by the position for the time being of said movable part, and on the track and in connection with specific different parts thereof energizing 'means adapted to cause said speedlimiting electromagnetc device to be energized by said specific different currents at said specific different parts respectively, a specific part of the track including both a warning section in which said energizing means is adapted to cause said speed-limiting electromagnetic device to be energized by current such as to cause said mov-. able part to occupy said first position and also a stop section in which said energizing means is adapted to cause said speed-limiting electromagnetic device to be energized by current such as to cause said movable part to occupy said second position.

9. Electrical train-controlling apparatus comprising on a train a danger-indicating device adapted to tend constantly to produce a danger-indicating operation, electromagnetic restraining means adapted when energized to restrain the operation. of said dangerdndicating device, a speed-responsive part adapted to change its position in accordance with the speed of the train, a

speed-limiting electromagnetic device adapted, in accordance with its energization by specific different currents corresponding respectively to spec fic different speed limits, to cause its movable part to occupy specific different speed-limiting positions, direction-corresponding part adapted to changeits position in accordance with the direction of running of the train, and ourrent-receiving means adapted to be energized by track current and when energized to cause the energization of said speed-limiting electromagnet c devlce, and on the track and in connection with specific different parts thereof energizing means adapted to -ause said current-rewiring means to be energized by specific dilferent currents in dif ferent pairs whereof each corresponds to a specific speed limit and the members of each dil 'er in accordance with the direction in which it is intended that said train should run, said speed-responsive part, said movable part of said speed-limiting electromag netic device, and. said direction-corresponding part being adapted to co-operate in including said electromagnetic restraining means electrically in circuit and so causing its energization only when said speedresponsive part is occupying a position that corresponds to a speed not greater than the speed limit corresponding to the position for the time being of said movable part of said speeddimiting electromagnetic device and said direction-corresponding part is in a position corresponding to the current for the time being energizing said current-receiving means and consequently to the direction in which it is intended said train should run.

10. In train controlling apparatus comprising a train-carried device the production of a danger indication by which dependent upon the condition as to electrification of apparatus on the train,,means adapt d to provide alternative independent track routes any one of whichmay be used for transmitting current to allect the condition as to electrification of said apparatus on the train as required in respect of said danger indication so that the control of the train by said train-carried device in the normal manner can be produced from the track as long as any of said routes remain intact, substantially as described.

11. Electrical train-controlling apparatus comprising an electromagnetic device adapted when tie-energized to allow its movable part to produce a danger-indicating operation, energizing means for energizing said electromagnetic device, an electrically operatable line-clea indicator, and means adapted to enable said movable part, when said electromagnetic device is (lo-energized, to complete a current path including said line-clear indicator and adapted when completed to connect said line-clear indicator in circuit with said energizing means so that on the subsequent energization of said electromagnetic device said line-clear indicator will be operated by current flowing through said path from said energizing means, said currentpath being adapted to be broken after the energization, and until the next de-energization, of said electromagnetic device, substantially as described.

Signed at London, England, this 9th day of December, 1921..

ARTHUR REGINALD ANGUS.

iii) 

